Jawaharlal Nehru Technological University Hyderabad 2003 B.Tech Aeronautical Engineering I Supplementary s, ember- ENGINEERING PHYSICS - Question Paper

Code No.NR-10103
I B.Tech. Supplementary Examinations, November-2003

ENGINEERING PHYSICS
(Common to Civil Engineering, Mechanical Engineering, Aeronautical Engineering, Chemical Engineering, Production Engineering, Mechatronics Metallurgy and Material Technology)
Time: three hours Max.Marks: 80
ans any 5 ques.
All ques. carry equal marks
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1.a) Distinguish ranging from Fresnel diffraction and Fraunhofer diffraction.
b) Give the theory of a plane transmission grating and define how it is used to determine the wavelength of light.
c) Calculate the aperture of the objective of a telescope that may be used to resolve stars separated by 4.88 ? 10-6 radian for the light of wavelength 600 nm.

2.a) Explain the terms: (i) plane polarized light (ii) optic axis (iii) negative crystals
and (iv) positive crystals.
b) Explain Malus legal regulations of polarization.
c) Find the polarizing angle for a transparent medium of refractive index 1.732, when the surrounding medium is air.

3.a) Explain the terms (i) acceptance angle and (ii) numerical aperture for an optical fiber, and derive the expressions for them.
b) Draw the block diagram of an optical fiber communication system, and discuss its function.

4.a) What is meant by polarization mechanism in dielectrics?
b) What is dielectric loss? Derive an expression for dielectric loss.
c) Write a short notes on porcelain.

5.a) Explain ‘relaxation time’, ‘collision time’ and ‘mean free path’ as applied to free electrons.
b) Write the main assumptions of Sommerfeld’s quantum theory of free electrons.
c) The subsequent data is known for aluminium: (i) the number of electrons per cubic metre = 18.10 ? 1028 (ii) the mobility of electrons = 1.32 ? 10-3 m2/V/S compute the resistivity of aluminium.

6.a) What are ferromagnetic materials?
b) Discuss hysteresis of a ferromagnetic material.
c) Describe the characteristic features of soft and hard magnetic materials.
7.a) What is meant by superconductivity? discuss Meissner effect.
b) Give the significance of London’s formula in superconductivity.
c) A superconductor has a critical temperature of 3.7 K in zero magnetic field and a critical field of 0.0306 Tesla at 0 K. obtain the critical field at two K.

8. Write short notes on any 4 of the following:
(a) Young’s double slit experiment
(b) Production of Ultrasonics
(c) Characteristics of laser light
(d) BCS theory of super conductivity
(e) Plastic deformation
(f) Mechanism of Creep.

Earning:   Approval pending.